Buzzing Sound in Recordings
Hi AudioMoth Team, I have 2 AudioMoth Dev's running the AudioMoth-USB-Microphone v1.3.1, and no matter what I do I get buzzing noise. I tried gain, changing sampling rates, filtering, I messed around with AudioMoth Live and Play apps, nothing solves the problem. I took them outside and powered them with a battery and the sound remains. I have tried them with a Mac, a Windows laptop, a microcontroller, different USB cords and ports, etc. I noticed this post: https://www.openacousticdevices.info/support/configuration-support/buzzzing-sound-white-recording I am certain mine have never experienced water damage, and I have had this noise since I opened them. I assumed it was user error and that I would solve it at a later date, but nothing I have tried works. It can get better than it is in these recordings, but not by much.
Here are recordings from each of them, taken at 48KHz with Gain @ Low with no filters and no advanced settings, LED enabled. I was about 40cm away from the mics.
AudioMoth Dev Unit A Device ID: 24E1440163FB90BF AudioMoth Dev Unit B Device ID: 24E1440163FAFE5C Please let me know how to proceed, thank you so much!
Hi Alex, The signal moves when I change to 96KHz or higher, it is then concentrated around 32 KHz. I started another recording indoors and walked outside, as I stepped outdoors the sound vanished. I then put the device into an ESD bag and walked back indoors and the sound returned but much lower intensity. I had tested it outdoors before but that was awhile ago and there could have been other stuff going on out there. Today it was relatively quiet. I also put my phone in airplane mode. I noticed its significantly worse by the entrance to the building and a bit worse near the entrances to specific rooms. My complete guess of a hypothesis is that its EMI from the door keycard tap system and probably other stuff. Hope this helps others. I have now covered the device in Kapton tape and I will then wrap it in aluminum foil. Best, Hudson